Classifications

• • C—CHEMISTRY; METALLURGY
  • C05—FERTILISERS; MANUFACTURE THEREOF
  • C05C—NITROGENOUS FERTILISERS
  • C05C9/00—Fertilisers containing urea or urea compounds
• • C—CHEMISTRY; METALLURGY
  • C05—FERTILISERS; MANUFACTURE THEREOF
  • C05G—MIXTURES OF FERTILISERS COVERED INDIVIDUALLY BY DIFFERENT SUBCLASSES OF CLASS C05; MIXTURES OF ONE OR MORE FERTILISERS WITH MATERIALS NOT HAVING A SPECIFIC FERTILISING ACTIVITY, e.g. PESTICIDES, SOIL-CONDITIONERS, WETTING AGENTS; FERTILISERS CHARACTERISED BY THEIR FORM
  • C05G3/00—Mixtures of one or more fertilisers with additives not having a specially fertilising activity
  • C05G3/90—Mixtures of one or more fertilisers with additives not having a specially fertilising activity for affecting the nitrification of ammonium compounds or urea in the soil
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S71/00—Chemistry: fertilizers
  • Y10S71/902—Nitrification inhibition

Definitions

• the invention relates to an improved formulation for a fertilizer additive concentrate. More specifically, the invention involves the composition of a solution of a phosphoramide in a solvent which is a glycol or glycol derivative with or without the presence of nonionic surfactants which are alkylaryl polyether alcohols, or mixed solvents of such glycol or glycol derivative with a liquid amide. Again, the mixed solvent can contain nonionic surfactants which are alkylaryl polyether alcohols. N-alkyl thiophosphoric triamides inhibit the activity of the urease enzyme. The urease enzyme catalyzes the decomposition of urea-based fertilizers to ammonia and the ammonium ion.
• the improved composition of the invention increases the nitrogen uptake efficiency of plants, enhances crop yields, and minimizes the loss of fertilizer-derived nitrogen.
• the N-alkyl thiophosphoric triamide is impregnated onto a granular fertilizer formulation by blending the concentrated solution of N-alkyl thiophosphoric triamide in a solvent selected from the group consisting of a glycol or glycol derivative or a mixed solvent comprising a glycol or glycol derivative and a liquid amide.
• a solvent selected from the group consisting of a glycol or glycol derivative or a mixed solvent comprising a glycol or glycol derivative and a liquid amide.
• These solutions can include such alkylaryl polyether alcohols as nonionic surfactants.
• the above mentioned solutions of the urease inhibitor can be mixed with liquid fertilizer compositions containing urea-based fertilizers.
• Nitrogen is an important plant nutrient. In addition to phosphorus, potassium, and other nutrients, nitrogen is needed to support the growth and development of plant life. Some plants, such as legumes, through a symbiotic relationship with Rhizobium bacteria take up elemental nitrogen from the atmosphere and fix this nitrogen into the soil. However, most plants grown to produce human and animal food require the use of nitrogen fertilizer in order to sustain their agricultural production.
• urea CO(NH 2 ) 2
• crops such as, corn, wheat and rice.
• urea When applied to moist soil, the urea becomes a source of ammonia as a result of hydrolysis catalyzed by urease, an enzyme produced by numerous fungi and bacteria.
• the reaction may be written as follows: ##STR1##
• urea as a source of these nitrogen nutrients to support the growth of crop plants relate to the rapid catalytic hydrolysis of urea to ammonia and carbon dioxide.
• the premature conversion of urea into ammonia contributes to the low efficiency (as low as 40 percent under some conditions) with which crop plants utilize urea-based fertilizer nitrogen.
• the worse conditions for nitrogen losses to ammonia volatilization are the application of urea-based fertilizer to moist soil followed by a number of days of drying conditions. This scenario allows for the conversion of the urea to ammonia on the surface of the soil without subsequent rainfall that would facilitate the conversion to ammonium and adsorption by the soil.
• Examples of mechanisms by which nitrogen can be lost from the soil include loss of ammonia through volatilization to the atmosphere and loss of nitrate through leaching to the subsoil by rainwater and/or through denitrification, i.e., bacterial conversion of nitrate to elemental nitrogen.
• Another drawback related to rapid hydrolysis of urea is the potential for excessive accumulation of ammonia in the soil shortly after seeding which may damage germinating seedlings and young plants.
• the prior art offers three approaches to make nutrient nitrogen derived from urea-containing granular fertilizers available to root systems of plants throughout their growing season: (1) multiple fertilizer applications; (2) synthetically produced, controlled release fertilizers; and (3) the incorporation of urease inhibitors or nitrification inhibitors into the fertilizer formulation. There are certain limitations and disadvantages associated with each of these approaches advocated by the prior art.
• the first approach involves the use of multiple fertilizer applications during the course of a crop growth season.
• Such multiple fertilizer applications can provide adequate nitrogen to meet the demand of growing plants, but they do so at the expense of higher fertilizer costs, higher fertilizer application costs, and the adverse environmental impact associated with the loss of nitrogen through nitrate leaching to the subsoil and ammonia volatilization.
• the second approach to extending the availability of nutrient nitrogen to crop plants over a longer period of time involves the use of controlled release granular fertilizers.
• fertilizers in this category there are two types of fertilizers in this category, namely, coated and noncoated fertilizers.
• the patent literature provides numerous references to prior art methodology for the production of coated controlled release fertilizers. The oldest of these is the use of molten sulfur to produce sulfur-coated nitrogen fertilizer pellets having a controlled fertilizer dissolution rate.
• the process comprises applying a coating of sulfur to fertilizer pellets and subsequently top-coating the resultant particles with an oily sealant to impregnate any cracks and voids in such sulfur coating.
• a sulfur shell is formed which is nearly impervious to water and suitable for regulating the dissolution rate of the nitrogen fertilizer, and thereby extending its availability to the plants.
• Numerous other patents describe methods to improve the efficiency of the sulfur coating process.
• Other coated fertilizer technology comprises the use of polymers to provide the coating for the fertilizer particles. These products have many advantages because the release of nitrogen through the coating is controlled by diffusion through the semi-permeable membrane. Therefore, the rate of nitrogen release can be controlled by the composition and thickness of the polymer coating.
• a new technology known as Reactive Layer Coating (RLC) is based upon the deposition of polymeric diphenylmethane diisocyanate onto the fertilizer particles followed by the deposition of a second coating of polyethyleneterphthalate.
• the non-coated fertilizers that have been or are being used as controlled release fertilizers comprise synthetically altered urea fertilizers.
• the oldest of these technologies are urea-formaldehyde reaction products and methylene ureas or methylene diurea/dimethylene triurea (MDU/DMTU) compositions.
• Urease inhibitors are compounds capable of inhibiting the catalytic activity of the urease enzyme upon urea in moist soil.
• phosphoric triamide compounds disclosed in U.S. Pat. No. 4,530,714.
• An example of an effective urease inhibitor disclosed in the U.S. Pat. No. '714 patent is N-(n-butyl)thiophosphoric triamide, which will be referred to herein as NBPT.
• NBPT When incorporated into a urea-containing fertilizer, NBPT reduces the rate at which urea is hydrolyzed in the soil to ammonia.
• the benefits realized as a result of the delayed urea hydrolysis include the following: (1) nutrient nitrogen is available to the plant over a longer period of time; (2) excessive build up of ammonia in the soil following the application of the urea-containing fertilizer is avoided; (3) the potential for nitrogen loss through ammonia volatilization is reduced; (4) the potential for damage by high levels of ammonia to seedlings and young plants is reduced; (5) plant uptake of nitrogen is increased; and (6) an increase in crop yields is attained.
• the liquid compositions of the U.S. Pat. No. '714 patent can contain complex ether alcohols as dispersing or emulsifying agents.
• NBPT has not been commercially used heretofore as an additive in liquid or granular urea.
• a major reason for this is the lack of a suitable method for the preparation of such NBPT-containing urea-based fertilizers which stems from certain physical and chemical characteristics of industrial grade NBPT which render this material difficult to handle.
• Industrial grade NBPT is a waxy, sticky, heat-sensitive and water-sensitive material. Consequently, the material is susceptible to decomposition during storage and distribution.
• the use of a liquid formulation of the NBPT is highly desirable because it greatly facilitates the introduction of the NBPT onto granular urea and into liquid fertilizers containing urea.
• NBPT urea-ammonium nitrate solutions
• An object of the invention is to provide a formulation for N-alkyl thiophosphoric triamides that will readily allow for their impregnation onto urea-containing solid fertilizer and allow for their easy incorporation into liquid fertilizer formulations containing urea.
• This formulation facilitates the application of N-alkyl thiophosphoric triamides which, in turn, eliminates the use of high amounts of urea-containing nitrogen fertilizer that are currently used to assure that crop yields are not limited by the availability of nitrogen as a plant nutrient or the use of higher cost controlled release fertilizers for more efficient application of urea-based nitrogen fertilizers.
• Another object of the invention is to provide a formulation that will allow for the introduction of N-alkyl thiophosphoric triamides into urea-based liquid fertilizers or for the impregnation of solid urea fertilizer, the performance of which is characterized by low ammonia volatilization losses.
• a further object of the invention is to provide methods of impregnating urea-containing solid fertilizer with the invention formulations or incorporating the invention formulations into liquid fertilizer formulations containing urea.
• the invention involves an improved homogeneous formulation comprising N-alkyl thiophosphoric triamide and a glycol or glycol derivative.
• the glycol or glycol derivative is a solvent for the N-alkyl thiophosphoric triamides.
• the invention formulation can also contain an additional solvent belonging to the group consisting of liquid amides, 2-pyrrolidone and N-alkyl 2-pyrrolidones.
• the invention formulation can optionally contain other additives, such as, a dye, a nonionic surfactant selected from the group consisting of alkylaryl polyether alcohols, and/or micronutrients.
• the alkylaryl polyether alcohols are those where the alkyl groups have from 6 to 16 carbon atoms and the average number of ethylene oxide units in the side chain are from 6 to 30 moles.
• the preferred nonionic surfactants are the octylphenol polyether alcohols.
• the invention method also involves applying the homogenous concentrated formulation of the invention to a solid urea-containing fertilizer composition or incorporating the homogeneous concentrated formulation of the invention into a liquid urea-containing fertilizer composition.
• the invention provides an improved formulation for the group of N-alkyl thiophosphoric triamide urease inhibitors described in U.S. Pat. No. 4,530,714.
• the pertinent portions of U.S. Pat. No. 4,530,714 are incorporated herein by reference.
• the invention formulation is comprised of at least one N-alkyl thiophosphoric triamide and at least one glycol and/or glycol derivative.
• the formulation can also contain at least one additional solvent belonging to the group consisting of liquid amides, 2-pyrrolidone, and N-alkyl 2-pyrrolidones.
• the formulation can optionally contain other additives, such as, at least one dye, at least one nonionic surfactant selected from the group consisting of alkylaryl polyether alcohols, or at least one micronutrient.
• additives such as, at least one dye, at least one nonionic surfactant selected from the group consisting of alkylaryl polyether alcohols, or at least one micronutrient.
• the use of the invention formulations offer a number of advantages such as: (1) improved stability of the active ingredient urease inhibitor; (2) excellent solubility characteristics; (3) extremely low flammability and toxicity of the solvents which greatly simplifies the handling and storage of the concentrate; (4) excellent cold temperature storage characteristics with the addition of the liquid amide co-solvent; and (5) good adsorption characteristics onto the solid urea containing fertilizers and excellent miscibility with liquid urea containing fertilizer formulations.
• N-alkyl thiophosphoric triamide refers not only to the N-alkyl thiophosphoric triamide in its pure form, but also to commercial grades of the material which can contain up to 50 percent (or less), preferably not more than 20 percent, of impurities, depending on the method of synthesis and purification scheme(s), if any, employed in the production.
• the preferred glycols or diols can be preferably represented by the general formula C n H 2n (OH) 2 , where n is 2 or more (preferably n is 2 to 6).
• glycols is applied, in general, to aliphatic dihydroxy (dihydric) alcohols.
• glycols examples include ethylene glycol (glycol), propylene glycol (1,2-propanediol), 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 1,7-heptanediol, 1,9-nonanediol, 1,8-octanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2,4-pentanediol, 2,5-hexanediol, 4,5-octanediol and 3,4-hexanediol.
• ethylene glycol glycol
• propylene glycol 1,2-propanediol
• 1,4-butanediol 1,5-pentanediol
• noncyclic glycols examples include neopenty glycol, pinacol, 2,2-diethyl-1,3-propanediol, 2-ethyl-1,3-hexanediol, 2-ethyl-2-butyl-1,3-propanediol, isobutylene glycol, 2,3-dimethyl-1,3-propanediol, 1,3-diphenyl-1,3-propanediol, 3-methyl-1,3-butanediol.
• cyclic glycols examples include 1,4-cyclohexanedimethanol and p-xylylene glycol.
• polyglycols are polyethylene glycols and polypropylene glycols.
• glycol (diol) derivatives which are esters are ethylene glycol monostearate, ethylene glycol distearate, ethylene glycol amido stearate, propylene glycol monostearate, propylene glycol dicaprylate, propylene glycol dicaprate diacetate glycol, dilaurate glycol, dipalmite glycol, diformate glycol, dibutyrate glycol, dibenzorate glycol, dipalmate glycol, dipropionate glycol, monoacetate glycol, monopalmitate glycol and monoformate glycol.
• Diethylene glycol monostearate is also an ester derivative.
• polyglycol (polydiol) derivatives which are esters are polyethylene glycol (PEG) 200-6000 mono and dilaurates, such as, PEG 600 dilaurate, PEG 600 monolaurate, PEG 1000 dilaurate, PEG 1000 monolaurate, PEG 1540 dilaurate and PEG 1540 monolaurate, polyethylene glycol 200-6000 mono and dioleates, such as, PEG 400 monoleate, PEG 600 dioleate, PEG 600 monooleate, PEG 1000 monoleate, PEG 1540 dioleate, PEG 1540 monooleate and polyethylene glycol 200-6000 mono and distearates, such as, PEG 400 distearate, PEG 400 monostearate, PEG 600 distearate, PEG 600 monostearate, PEG 1000 distearate, PEG 1000 monostearate, PEG 1500 monostearate, PEG 1540 distearate, PEG 1540 monostearate and PEG 3
• Glycerol (glycerine) is a triol glycerol.
• glycerol esters are glycerol monostearate, glycerol distearate, glycerol monooleate, glycerol monolaurate, glycerol dilaurate, glycerol dipalmitate, glycerol monopalmitate, glycerol triacetate, glycerol tribenzoate, glycerol tributyrate, glycerol trimyristate, glycerol trioleate, glycerol trilaurate, glycerol tripalmitate and glycerol tristearate.
• the glycol or glycol derivative content of the composition of this invention is between about 99 percent by weight and about 50 percent by weight, and preferably between about 70 percent by weight and about 80 percent by weight, when present as the sole component of the formulation other than the N-alkyl thiophosphoric triamide urease inhibitor.
• the N-alkyl thiophosphoric triamide content of the composition is between about 1.0 percent by weight and about 50 percent weight, and preferably between about 20 percent by weight and about 30 percent by weight.
• the formulation can contain a co-solvent chosen from the group consisting of liquid amides, 2-pyrrolidone and N-alkyl 2-pyrrolidones.
• the optional mixed solvent formulation can contain one of the "liquid amides" in a concentration of between about 0.5 percent by weight and about 30 percent by weight, and preferably between about 5 percent by weight and about 20 percent by weight, together with the N-alkyl thiophosphoric triamide in the same concentration ranges described for the concentrate with the glycol or glycol derivative as the sole solvent.
• the balance of the mixed solvent would then consist of one of the solvents selected from the group of glycols and glycol derivatives.
• the mixed content of the composition of the invention is between about 99 percent by weight and about 50 percent by weight, and preferably between about 70 percent by weight and about 80 percent by weight, based upon the only other component of the formulation being the N-alkyl thiophosphoric triamide urease inhibitor.
• the N-alkyl thiophosphoric triamide concentration formulation can also optionally contain other additives, such as, a dye(s), a nonionic surfactant(s) selected from the group consisting of alkylaryl polyether alcohols, and a micronutrient(s).
• a dye(s) such as, a dye(s), a nonionic surfactant(s) selected from the group consisting of alkylaryl polyether alcohols, and a micronutrient(s).
• the concentration range will be between about 1.0 percent by weight and about 20 percent by weight, based upon the total weight of the composition, with a preferred concentration range between about 8 percent by weight and about 15 percent by weight, based upon the total weight of the composition.
• N-alkyl thiophosphoric triamides are often waxy and sticky materials, and as such are difficult to handle in conventional industrial equipment.
• N-alkyl thiophosphoric triamides are poorly soluble in water, in aqueous solutions, such as ammonium hydroxide solutions, and in numerous organic solvents, such as, toluene, benzene, hexane, dichloromethane, and others.
• the lower alcohols are good solvents for the N-alkyl thiophosphoric triamides, but they are flammable and present safety problems.
• the N-alkyl thiophosphoric triamides have proven to be unstable in many aqueous and non-aqueous solvents.
• N-alkyl thiophosphoric triamides exhibit exceptional solubility and stability in solvents selected from the group of glycols and glycol derivatives.
• R 1 is a hydrogen atom or an alkyl group having up to 4 carbon atoms and wherein R 2 and R 3 are independently hydrogen atoms, alkyl (preferably C 1 -C 6 ) groups or phenyl groups, 2-pyrrolidone, and N-alkyl 2-pyrrolidones wherein the alkyl group ranges in size from one to twelve carbon atoms, to the formulation improve the cold temperature flowability of the formulation with no significant loss in the stability of the formulation.
• nonionic surfactants selected from the group consisting of alkylaryl polyether alcohols can impart certain desirable characteristics such as enhanced stability to the formulation(s).
• These solutions can be stored over extended periods of time and can conveniently serve as a vehicle to impregnate the N-alkyl thiophosphoric triamide onto urea based solid fertilizers using a variety of fertilizer bulk blending equipment commonly available with fertilizer dealers and distributors. Any suitable or conventional equipment can be used to apply the formulation to the solid fertilizer. Preferably the addition provides a thorough impregnation of the solid fertilizers by the formulation.
• Any suitable or conventional equipment can be used to incorporate the formulation into the liquid fertilizer.
• liquid amides used in the practice of this invention include formamide, N,N-dimethyl formamide, N,N-dimethyl acetamide and N-butyl N-phenyl acetamide.
• the N-alkyl 2-pyrrolidones used in accordance with this invention are five-membered heterocyclic organic compounds with one nitrogen atom per ring, with an oxygen atom bonded to a ring carbon atom adjacent to the nitrogen, and with an alkyl group ranging in size from one to twelve carbon atoms bonded directly to the nitrogen atom.
• N-alkyl 2-pyrrolidones which can be used as NBPT solvents in practicing this invention include N-methyl 2-pyrrolidone, N-octyl 2-pyrrolidone, and N-dodecyl 2-pyrrolidone.
• the preferred "liquid amide" solvent used in the practice of this invention is N-methyl 2-pyrrolidone.
• N-alkyl thiophosphoric triamide solutions in solvents of this invention remain stable over extended periods of time and over temperatures ranging from about 30° F. to about 120° F.
• the concentrated solutions of this invention can be managed using conventional liquid storage, transportation, and pumping equipment.
• the amount of concentrated N-alkyl thiophosphoric triamide solution added to either solid or liquid urea-based fertilizer compositions in accordance with this invention depends on the desired N-alkyl thiophosphoric triamide content of the fertilizer composition and on the N-alkyl thiophosphoric triamide content of the concentrated solution. This can be readily calculated by those skilled in the art.
• NMP N-methyl pyrrolidone
• the invention solvents consisting of (i) glycols and (ii) glycols with a co-solvent comprised of a "liquid amide” as defined in this specification have proven to be superior.
• the solvents used by the invention are also superior to the delivery systems of U.S. Pat. Nos. 5,071,463 and 5,160,528.
• a primary distinction between the current invention and the known patents related to coated fertilizer products are the cost of the coated fertilizers.
• Such prior art coated fertilizers are speciality products that are only used in very limited applications because of their high cost.
• the use of the urease inhibitors with urea are considerably cheaper and are designed for general crop applications.
• the reference to fertilizers containing urease inhibitors in such patents are for urease inhibitor containing fertilizers that are additionally polymer coated.
• the application of the various polymer coatings and the solvents used for these applications are totally different from the impregnation of urea with urease inhibitors.
• the current invention provides ease of application and enhanced economics as opposed to the prior art coated fertilizers.
• NBPT N-(n-butyl) thiophosphoric triamide
• N-(n-butyl) thiophosphoric triamide used in this test was industrial grade NBPT which contained about 89 percent of active ingredient and had the waxy and sticky appearance previously described for these materials. Nevertheless, the dissolution proceeded easily in all cases.
• the long term stability results at three different temperatures for each of the solvents or solvent systems are shown in Table I below.
• the solvent or solvent systems used in this example are described as follows:
• NP-100 one of the class of octylphenol polyether alcohol nonionic surfactants previously disclosed in the description of the invention.
• NP-100 is marketed by Witco and is poly(oxy-1,2-ethanediyl)-alpha (nonylphenyl)omega-hydroxy.
• NMP N-methyl pyrrolidone
• glycols represented by propylene glycol or dipropylene glycol
• the glycols provide the balance of the composition of the formulation in each case.
• This example illustrates the method of this invention for the incorporation of NBPT onto a homogenous urea-based granular fertilizer composition.
• a solution of 25 percent of active ingredient NBPT was prepared by dissolving the industrial grade NBPT into propylene glycol. This concentrated NBPT solution was pumped onto granular urea in commercial blending equipment at a fertilizer dealers plant.
• a dye 0.1 percent of FD&C green dye #3
• was included in the formulation to provide a means to observe the distribution of the NBPT concentrate on the urea. Visual observation of the impregnated urea indicated that the NBPT was uniformly distributed onto each granule of the product over a period of about 2 to 3 minutes contact in the blender. This observation was substantiated by the assay of three grab samples from the blended urea which showed analyses of 990, 1000, and 1030 ppm.
• NMP N-methyl pyrollidone

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Soil Sciences (AREA)
• Pest Control & Pesticides (AREA)
• Fertilizers (AREA)
• Agricultural Chemicals And Associated Chemicals (AREA)

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• 1995
  • 1995-12-19 US US08/575,025 patent/US5698003A/en not_active Expired - Lifetime
• 1996
  • 1996-12-10 CA CA002240284A patent/CA2240284C/en not_active Expired - Lifetime
  • 1996-12-10 BR BR9612034-7A patent/BR9612034A/pt not_active IP Right Cessation
  • 1996-12-10 ES ES96943561T patent/ES2329201T3/es not_active Expired - Lifetime
  • 1996-12-10 NZ NZ324974A patent/NZ324974A/xx not_active IP Right Cessation
  • 1996-12-10 CN CNB961990015A patent/CN1163442C/zh not_active Expired - Lifetime
  • 1996-12-10 JP JP52283297A patent/JP3282149B2/ja not_active Expired - Fee Related
  • 1996-12-10 KR KR10-1998-0704111A patent/KR100419454B1/ko not_active IP Right Cessation
  • 1996-12-10 WO PCT/US1996/019223 patent/WO1997022568A1/en active IP Right Grant
  • 1996-12-10 DE DE69637957T patent/DE69637957D1/de not_active Expired - Lifetime
  • 1996-12-10 EP EP96943561A patent/EP0869933B1/en not_active Expired - Lifetime
  • 1996-12-10 AU AU12775/97A patent/AU708702B2/en not_active Expired
  • 1996-12-16 IN IN603BO1996 patent/IN186192B/en unknown
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